Passivity Control in Real-Time Hybrid Testing

This paper details the application of passivity control in stabilizing real-time hybrid test (RtHT) systems with linear and nonlinear physical substructures. The effectiveness of this novel application in hybrid systems is assessed in the time and frequency domains with special attention given to improvements in stability and tracking performance. A 1 degree-of-freedom system is chosen as a test case with transfer dynamics modelled as a pure delay. The application of passivity control widely used in the teleoperation industry has been found to stabilize the hybrid test system under a wide range of operating conditions whilst resulting in tracking improvements as well. Unlike conventional model based compensation schemes, the application of passivity control does not require any information about the transfer system and/or physical substructure making this technique practical and effective in compensating complex hybrid tests where accurate linear models are unavailable.